In the interests of full disclosure: I am wary – an acquired wariness; all tastes are acquired – of the novel as platform. Legitimately, editorials are platforms, opinion pieces are platforms, blogs are platforms. But fiction that announces its debate too loudly risks simplification. “Subtle”, “complex” and “nuanced” are almost always positive critical terms.

Chimamanda Ngozi Adichie’s Half of a Yellow Sun (the 2006 Orange Prize winner) was subtle, complex and nuanced. The book dealt with the experiences of Igbo civilians during the Biafran war. It was a tense, high-wire walk of a novel that took in politics and history without forgetting the primacy of the personal. With Americanah, Adichie has chosen to loosen that tightrope – to step on to the more dangerous slackrope. The heroine, Ifemelu, and her first love, Obinze, grow up in modern-day Nigeria. During university strikes, Ifemelu decides to continue her studies in the US; after graduating, Obinze moves to Britain. Both are intelligent, educated and middle class: compelled to emigrate not by conflict or poverty but by “the oppressive lethargy of choicelessness”.

For many years Ifemelu and Obinze lose touch, and the bulk of the novel is dedicated to charting their experiences in the US and the UK. Ifemelu gets the most airtime. She eventually becomes a famous blogger writing “Various Observations About American Blacks (Those Formerly Known as Negroes) by a Non-American Black” – a blog started after her enthusiastically received post on happilykinkynappy. com (devoted to natural African hair). “Posting on the website was like giving testimony in church; the echoing roar of approval revived her.” Her blog posts – many are included in the novel – have a deliberately preachy flavour, more parable than anecdote. Sample opening line: “So this guy said to Professor Hunk, ‘White privilege is nonsense. How can I be privileged?’”

Although the blog posts are clearly Ifemelu’s polemics, and although the narrative surrounding them is more (to use that word again) nuanced, the subject of the book is race. At times, it feels like an anthology of examples – an agglomeration rather than an arrangement. We have the under-representation of black women in fashion magazines, the white woman who indiscriminately calls black women “beautiful”, the black man who insults Ifemelu for her “jungle” look (ie, non-westernised hair), the absurdity of privileged westerners treasuring roughly finished ethnic tableware.

No issue is left uncovered. Everything is held to account. And Adichie’s observations are always sharp, intelligent, humorous and humane. They will challenge the way you think about race and show you a radically defamiliarised version of western society, as seen through African eyes.

An issues novel, then, that is unashamedly open about its intentions. Formally, Americanahis baggy. The story often feels like a vehicle for the discussion. There are wobbles, moments when the whole book risks losing its balance. Adichie is aware of the danger. For readers uncomfortable with the novel’s relentness focus, she includes what seems to be a small manifesto, or perhaps even a warning. Shan, an African-American writer, is annoyed when her white editor wants to change various anecdotes in her memoir.

“He says it’s not subtle. Like life is always fucking subtle,” Shan tells her friends. “He thinks we should complicate it, so it’s not race alone. And I say, but it was race . . . ‘Nuance’ means keep people comfortable so everyone is free to think of themselves as individuals and everyone got where they are because of their achievement.”

Adichie is a very skilful writer and her talent for illuminating the intricacies of human interactions carries her. Although I will continue to prefer the elegance displayed in Half of a Yellow Sun, this bold book is – among many other things – an important reminder of the privilege inherent in that preference.

It sounded like the densest of abridgements: five days of excerpts from Reality Is Not What It Seems: the Journey to Quantum Gravity by the Italian theoretical physicist Carlo Rovelli (week beginning 28 November, 9.45am). Swarms of quantum events where time does not exist. Cosmology, meteorology and cathedrals of atomism. Leucippus of Miletus and lines of force filling space. Very few of us listening could have understood what was being said. Instead, we just allowed it to wash over, reminding us that there are more things in heaven and earth, Horatio.

Perhaps once or twice, as the week progressed, token attempts were made to check that everybody was keeping up (“So, the number of nanoseconds in a second is the same as the number of seconds in 30 years”) – or to encourage listeners to picture themselves as part of an experiment (“Imagine I’m on Mars, and you were here . . .”). But generally it was utterly airtight, the reader, Mark Meadows, doing a good job of keeping his voice at a pace and tone uncondescendingly brisk, flattering us that nobody was scratching their head (“The speed of light determined by Maxwell’s equations is velocity with respect to what?”).

It was my favourite radio book reading of 2016. Not because I learned a single thing I could repeat, or might realistically mull over, but because it sounded like a brief return to something that has declined so much over our lifetimes – knowledge as part of a function of a media flow.

It’s that old idea that something might be there for your betterment. When we were exposed to just four channels on television especially, and forced to stay on them, we got into astronomy and opera and all sorts of stuff, almost against our will. (Rigoletto? Jesus. Well, there’s nothing else on . . .) The programme was marvellously and unapologetically impenetrable, as the days and chapters piled up relentlessly (“We are immersed in a gigantic flexible snail shell”). What this adaptation comprehended was that we don’t actually want someone explaining Einstein to us. What is much more compelling – more accurate and clever – is simply to show what it’s like in other people’s brains.

Antonia Quirke is an author and journalist. She is a presenter on The Film Programme and Pick of the Week (Radio 4) and Film 2015 and The One Show (BBC 1). She writes a column on radio for the New Statesman.